Whenever i even hear/see a fart..i cover my nose instantly..idk why tho :o
Just wondering if any other crunchies do it

you've probably developed a conditioned reflex after repeated exposure to hearing/seeing farts and covering your nose as a result to avoid the negative stimulus (i.e. smelling the fart)

this is called operant conditioning with negative reinforcement
your respone to cover your nose is strengthened because it is followed by the disappearance of the unpleasant stimulus (i.e. the smell of the fart) therefore, through repetitive action, you're now covering your nose instantly when you hear/see a fart whether real or not

in short.. he/she's got aLot experience when it comes to farts?

(heck, how do you deveLop that?! do peopLe around you fart aLL the time?!)